Commissioning of User Beamlines Begins

The commissioning of the experimental beamlines is now in progress. Beginning with SRI-CAT's bending-magnet beamline 1-BM, this process is expected to lead to the first fully operational beamlines later this year. As the APS gains experience with the commissioning process, the pace should accelerate. The excitement of "first light" is now being replaced by the anticipation of the many scientific payoffs to be realized in the months and years ahead.

The early part of the commissioning process has several basic, but vital, objectives. The first is to characterize the x-ray beam. To this end, SRI-CAT measured the source size using a pinhole, scintillator, and CCD detector to image the stored electron beam. Additional measurements, in which slits were scanned across the beam, yielded preliminary data on angular divergence.

When refined and fully analyzed, these measurements will provide valuable information to APS users and operators. Incidentally, during the studies, storage-ring operators demonstrated the ability to reliably reposition the x-ray beam on the pinhole from one day to the next.

Another important concern during commissioning is radiation shielding. Radiation physicists continually monitor the commissioning area to ensure that the radiation shielding is effective at protecting personnel. This monitoring will continue as higher and higher currents are stored during storage-ring commissioning.

A third area of emphasis is the Personnel Safety System (PSS) and other safety interlock systems. These engineered systems ensure safe operation of the APS facility by a combination of installed hardware and software systems to prevent inadvertent hazardous situations from occurring.